1. Field of the Invention
The present invention relates to a cleaning device for cleaning the discharge port face of an ink jet head which performs the recording by discharging the ink from recording means onto the recording medium, and an ink jet apparatus with the cleaning device mounted, and more particularly to a cleaning device with improved cleaning performance and an ink jet apparatus with the cleaning device mounted.
2. Related Background Art
Recording apparatuses having the features of printer, copying machine and facsimile, or recording apparatuses for use as the output device for a composite equipment or a work station containing a computer, a word processor and so on are configured to record the image (including characters or symbols) onto the recording sheet (recording medium) such as a paper or a plastic thin plate (e.g., OHP), based on image information. Such recording apparatuses can be classified into an ink jet system, a wire dot system, a thermal system, a thermal transfer system and a laser beam system, depending on the recording method for recording means used.
In a serial type recording apparatus which takes the recording system of scanning in a direction crosswise to the conveying direction of recording sheet (sub-scan direction), the image can be recorded on a desired range of the recording sheet in such a way as to, after setting the recording sheet at a predetermined recording position, repetitively perform the operation of recording the image (including characters or symbols) by recording means (recording head) mounted on a carriage moving (scanning) along the recording sheet, including recording one line, then feeding (sub-scanning) the sheet by a predetermined amount, and recording (scanning) the image at the next line. On the other hand, in a line type recording apparatus which performs the recording only by the sub-scanning of feeding the recording sheet in a conveying direction, the image is recorded over the recording sheet in such a manner as to set the recording sheet at a predetermined recording position, and then consecutively perform the operation including recording one line at a time, and feeding the sheet by a predetermined amount (pitch feeding).
Among them, an ink jet system (ink jet recording apparatus) which performs the recording by discharging the ink from recording means (recording head) onto the recording sheet has the advantages in which recording means can be made compact, the higher definition image can be recorded at a higher speed, the ordinary paper is usable for recording without needs of any special treatment, the running cost is low, there is less noise owing to the non-impact method, and the color image is easily recorded by using color inks. In particular, a line-type recording apparatus using recording means of the line type in which a number of discharge ports are arranged in a direction of the sheet width allows the recording to be made at higher speed.
Specifically, recording means (recording head) of the ink jet system of discharging the ink by the use of heat energy can be easily fabricated with an arrangement of liquid paths (discharge ports) at high density by forming electrothermal converters, electrodes, liquid path walls, and a ceiling plate as the film on a substrate through the semiconductor fabrication process including etching, vapor deposition and sputtering, and thus can be made more compact. Also, by utilizing the merits of the IC technology or micro-process technology, recording means can be easily lengthened, and readily made a full-multi configuration or higher density packaging.
In an ink jet recording apparatus which performs the recording by discharging the ink through fine discharge ports onto the recording sheet, the condition of the discharge port face of the recording head on which a plurality of discharge ports are arranged in a predefined array may have significant effects on the recording quality. That is, if the discharge port face is wet with the ink or water droplets, or has adherent foreign matter, ink droplets discharged may be deflected in the discharge direction, drawn by the wetting or foreign matter, or the normal discharge is prevented, resulting in a discharge failure (including undischarged). To remove such ink or foreign matter adhering to the discharge port face, it is common practice to wipe and clean the discharge port face with a wiper formed of a plate-like rubber elastic member at predetermined timings.
By the way, in the conventional ink jet recording apparatus, a blade made of rubber elastic material in a flat plate form disposed in parallel to the discharge port array is placed into contact with the discharge port face, and either the recording head or the blade is moved in parallel in a direction perpendicular to the discharge port array to cause the blade to slide on the discharge port face in a direction transverse to the discharge port array, thereby enabling the wiping operation. Therefore, at the wiping, the entire area of the discharge port array is brought into contact with the blade at the same timing, and cleaned off.
However, in such conventional ink jet recording apparatus, since the end face of blade is simultaneously brought into contact with the entire area of the discharge port array, it is considered that if there are more discharge ports and the blade (wiping member) is longer, as with the line recording head, for example, the blade is prone to deformation or distortion which makes it difficult to cause the blade to slide on all the discharge ports uniformly (evenly), thereby degrading the wiping function of the blade (wiping member).
Namely, unless the parallelism between the discharge port face of recording head and the contact face of blade is secured with high precision, the blade may not be placed evenly into contact with all the discharge ports of the lengthy head, resulting in unevenness of cleaning, or if the cleaning is repetitively executed over the long term, it may possibly have some effects on the condition of the discharge port face.